What is the adult intramuscular dose of epinephrine?

• A. 0.3 mg IM
• B. 0.3 mL IM
• C. 0.03 mg IM
• D. 1 mg IM

Answer: (A)

For an adult experiencing anaphylaxis, the recommended intramuscular dose of epinephrine is 0.3 mg. Epinephrine used for IM injection is at a 1:1000 concentration (1 mg per mL), so this 0.3 mg dose corresponds to a small volume (about 0.3 mL) if drawn up, but most EMS practice uses a fixed 0.3 mg IM dose per injection. This amount provides rapid alpha-adrenergic vasoconstriction to raise blood pressure and reduce mucosal edema, along with beta-adrenergic bronchodilation to improve breathing. A dose of 0.03 mg would be too small to treat an adult effectively, while 1 mg is unnecessarily large for a single IM dose. The emphasis is on delivering the 0.3 mg amount promptly to counter the life-threatening reaction.